Run the comparison in your own account. Segment conversion rate by landing page, then put the purpose-built campaign page next to the homepage for the same campaign.
The homepage wins often enough that it is worth explaining rather than dismissing. The page built specifically to convert paid traffic, with the distractions stripped out and the form above the fold, loses to the general-purpose page that was designed for everybody.
There are three reasons, and none of them are about button color.
Why the homepage keeps winning
The homepage answers who you are. It has the logos, the years in business, the service area, the phone number in the header, the navigation that lets a skeptical visitor go read about the team before deciding. Landing page orthodoxy strips all of that out to reduce distraction, and for a high-consideration service purchase, those distractions were doing load-bearing work.
The landing page was written from a campaign brief rather than a search term. Someone wrote it once, for a concept, in a planning document. The person clicking the ad typed six words into a phone at 9pm. Those two documents rarely say the same thing.
The landing page is frozen while the ads move. Keywords get added, negatives get applied, ad copy gets rewritten monthly. The page has not changed since launch, so the gap between what the ad promises and what the page says widens every month that the campaign is optimized.
A teardown
Here is the pattern in concrete form. A commercial plumbing client, an emergency services campaign, and a query typed at 9:40pm.
The search: emergency commercial plumber denver
The ad:
24/7 Emergency Commercial Plumbing Denver crews on call tonight. Licensed, insured, 60-minute response. Call now.
The landing page it points at:
Commercial Plumbing Solutions for Colorado Businesses With over two decades of experience serving the Front Range, our team delivers comprehensive plumbing services tailored to your facility's needs.
[Request a Consultation]
Five things break in the space between those two blocks.
The word emergency disappears. The searcher has water on a floor right now and the page opens with two decades of experience, which is a credential and not an answer.
The promise vanishes. The ad committed to a 60-minute response tonight. The page does not repeat it, which reads as a walk-back even if the company fully intends to honor it.
The action changes. The ad said call now. The page says request a consultation. A consultation is a scheduled thing that happens later, and the visitor did not come here to schedule something later.
The timeframe is gone. Tonight, now, on call, all absent. The page is written in the timeless voice of a brochure.
The phone number is below the fold on mobile, because the hero section is a headline, a subhead, and a form, and the form takes the whole screen.
Now the same page rewritten to match what the ad promised:
Emergency Commercial Plumbing in Denver, Tonight Licensed crews on call right now. We answer in minutes and target a 60-minute arrival across metro Denver.
[Call (xxx) xxx-xxxx] ยท [Or send details and we will call you back]
Same business, same offer, same credibility. It now says the thing the ad said, in the order the visitor needs it, with the action the visitor came to take.
Notice what did not change. The trust signals stay, they just move below the fold instead of leading. Twenty years of experience is a reason to choose you once you have established that you can come tonight. It is not a reason to keep reading when there is water on the floor.
The read-aloud test
The fastest way to catch this on your own account takes two minutes per ad group.
Open the ad copy and the landing page side by side. Read the ad headline out loud, then read the page headline out loud, back to back, with no pause. If the pair sounds like one continuous thought, the match is fine. If it sounds like two different companies talking, you have found the leak.
Do it for your top five ad groups by spend. In our audits this is where the largest single-change gains come from, well ahead of form length or layout experiments, and it costs nothing to fix.
What Google is already telling you
You do not have to guess at this. Google publishes landing page experience as one of the three components of Quality Score, alongside expected clickthrough rate and ad relevance, and each is reported as above average, average, or below average at the keyword level in your account.
Two useful clarifications from the same documentation. Quality Score is a diagnostic tool rather than a key performance indicator, and it is not itself an input in the ad auction. So do not set a target for it or report it monthly. Do read the component statuses, because a column full of below-average landing page experience on your highest-spend keywords is the platform naming the problem for you.
What to fix first on a small budget
Match the headline to the ad. It is free, it takes an afternoon, and it is the only change on this list with no downside.
Then restore the action the ad promised. If the ad says call, the page leads with a tappable number. If the ad says get a quote, the page leads with a short quote form and nothing else competing with it.
Then fix the mobile hero. Most emergency and after-hours traffic is on a phone, and a form that fills the entire first screen with the phone number buried underneath is a self-inflicted wound. That is also worth reading next to the wider audit of what breaks between a visitor and a submitted form, since a matched page pointing at a broken form fixes nothing.
Only after those three should anyone start testing layouts, and by then the gain is usually small. The broader principles still apply and we covered them in what makes a landing page convert, but principles are not the problem in most accounts. Message match is.
If the ads are running well and the pages behind them have not been touched since launch, that gap is where the budget is going. Our paid media team builds the campaign and the page it points at together rather than treating the page as someone else's deliverable. And if the pages match, the forms work, and the leads still are not turning into revenue, the problem sits elsewhere on the path from search to closed deal.